1. Field of the Invention
The present invention relates to a level detecting method for detecting if content (object to be measured) in a tank or the like has reached a specified level or not without making contact therewith, and its apparatus.
2. Prior Art
Conventionally, as this type of level detecting method and its appartus, contact type apparatuses have been employed, in which, for example, a rod element vibrating vertically at a specific frequency is disposed projecting from the wall into the inside of a tank containing content such as powder, granules, or lumps, and when the materials contacts with the rod element to restrict the vibration of the rod element, the vibration of the rod element is stopped by the content, so that it is detected that the content has reached to a specified level.
The apparatus of this type, however, has its own problems, that is, since the vibration of the rod element is designed to be restricted and stopped by being pressed by the content having its own weight, in the case of very light object such as feather and cotton, even if the object to be measured reaches a specified level, it is not detected at all.